Apparatus for throwing bulk material



Nov. 5, 1957 c, DOYER APPARATUS FOR THROWING BULK MATERIAL Filed Aug 22. 1955 FIG.3

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.C ORNELIS DOVER arm r United States Patent APPARATUS FOR THROWING BULK MATERIAL Cornelis Doyer, Bussum, Netherlands Application August 22, 1955, Serial No. 529,680

4 Claims. (Cl. 198-128) My invention rel-ates to apparatus for throwing bulk material to a delivery station. Throwing apparatus of this kind are already known, the material being thrown oif mainly by centrifugal force. The disadvantage of such known apparatus is that the material must be brought with a fairly high initial velocity into the centrifugal apparatus and that the velocity of the different parts of the material are different since they cannot all be thrown off from the periphery of the centrifugal wheel but are carried around by the latter at different distances from the axis of rotation of this wheel. As a result not all the particles are thrown oif over the same distance. A proper stream of material is therefore not obtained.

The invention has for its object to provide a throwing apparatus by means of which the material can be thrown freely through the air in an exact stream, the cross section of which varies only little from beginning to end.

The apparatus according to the invention comprises two cooperating endless belts arranged one above the other, the upper belt being provided with entraining elements and the lower belt extending farther in the direction of transport of the bulk material than the upper belt. In this apparatus all the particles of the material receive the same high speed and are thrown over substantially equal distances.

In a preferred embodiment of the invention the entraining elements of the upper belt are in the form of ribs arranged so that they substantially enclose spaces which diverge in the direction of travel of that portion of said belt which cooperates with the lower belt. The lower belt only may be driven, the upper belt being held in contact with the lower belt by pression. For that purpose the upper belt may be carried by arms hinged to the frame of the apparatus and permitting an upward movement of said belt.

For an understanding of the invention reference is made to the accompanying drawing which shows two embodiments of the invention.

Fig. 1 illustrates diagrammatically a throwing apparatus mounted on a vehicle.

-Fig. 2 is a cross-section of part of the throwing apparatus of Fig. 1.

Fig. 3 shows in a more detailed form another embodiment of the invention.

Fig. 4 is a plan View of the upper belt and its guiding means in the apparatus of Fig. 3.

Referring to the drawing, 1 is the vehicle frame provided with two rollers 2, 3 over which is guided an endless belt 4. One of the rollers is driven by a motor through a speed regulator. This motor and its regulator are also mounted on the frame 1 but are not seen in the drawing. The angle subtended between the direction of the endless belt and the horizontal plane is made adjustable by providing that the whole belt with its equipment can be turned about the axis of the roller 2. Adjacent the roller 2 is a hopper 6 for supplying the bulk material 7 to the belt. The effective part of the belt 4 has a channel-shaped transverse section (Fig. 2). Such a section facilitates concentration of the material toform an exact stream. For the purpose of ensuring a directing action and a uniform speed of the particles of the bulk material which helps the formation of the stream there is arranged over the conveyor belt 4 a second belt 11 which is led around rollers 12, 13. The lower belt is smooth, the upper belt which is considerably shorter than the lower belt is provided with ribs 15 corresponding to the channel form of the lower belt; the material at the end of the belt 4 is thrown off in a pure stream 8 and is moved freely through the air to a hopper 9 through which the material can be thrown into a truck 10.

Obviously the hopper 9 can be combined with some other device, e. g. a concrete-mixing machine.

Though, preferably, only the lower belt is driven while entraining the upper belt by frictional contact, the two belts 4 and 11 may be driven at substantially the same speed. This speed can be higher than 2 meters per second, e. g. 6 meters per second.

In the construction shown in Figs. 3 and 4 the upper belt 11 is pressed against the lower belt 4 by the provision of a hinged arrangement of the guiding rolls 1?. and 13. These rolls are carried by arms 16 and 17 respectively, which arms are hingedly connected to upright members 18 of the frame 1. To ensure a better contact between the two belts while maintaining the yielding properties of the upper belt permitting large particles to pass between the belts, intermediately of the rolls 12 and 13 the upper belt is guided by spaced rolls or discs 19 and 20 journaled in the upright members 18.

A preferred form of the rib arrangement on the upper belt is shown in Fig. 4. The ribs 15 substantially enclose spaces which diverge in the direction of travel of that portion of the upper belt which cooperates with the lower belt. It will be understood that, instead of the arrangement shown, the ribs may be, for example, V- shaped. These arrangements provide the ribs with the desired gripping action, necessary for imparting to the bulk material the required high velocity over the short available distance.

What I claim is:

1. An apparatus for throwing bulk material to a delivery station, comprising two co-operating endless belts arranged above each other in an inclined position, the lower of said belts extending beyond the upper of said belts in a predetermined direction of transport, drive means for imparting motion directly to at least one of said belts in such sense that a portion thereof nearest the other belt moves in said direction of transport, pressure means maintaining adjacent portions of said belts in contact with each other for simultaneous movement in said direction of transport, and a set of ribs on the upper of said belts extending substantially from the edge of said upper belt toward its center at an inclination to said edges, said ribs converging in a direction opposite to the sense of movement of said upper belt.

2. An apparatus for throwing bulk material to a delivery station, comprising an inclined lower endless belt, a pair of first rollers supporting said lower belt, a similarly inclined but shorter upper belt having a lower reach in contact with an upper reach of said lower belt, a pair of second rollers intermediate said first pair of rollers supporting said upper belt, drive means for imparting motion directly to at least one of said belts, and a pair of axially spaced additional rollers intermediate said second pair of rollers urging the edges of said lower reach of said upper belt into contact with corresponding edges of said upper reach of said lower belt.

3. An apparatus according to claim 2, wherein said upper belt is provided with ribs angularly inclined with respect to the belt edges, said ribs constituting substantially V-shaped formations diverging in the direction of movement of said upper 'belt.

4. An apparatus according to claim 2, wherein said second rollers extend completely across said upper belt, further comprising "pivotal mounting means for said second rollers enabling the latter to be lifted off said lower'belt.

References Cited in the file of this patent UNITED STATES PATENTS 

